Casing-wrench.



T. J. GRIFFIN.

GASING WRENCH.

APPLICATION FILED NOV. 0, 1912.

Patented Mar. 3, 1914.

JA 0772M 4/111 COLUMBIA l'umlm THOMAS J'. GRIFFIN, 013 LOS ANGELES, CALIFORNIA.

CASING-WRENCH.

Specification of Letters Patent.

Patented Mar. 3, 1914.

Application filed November 9, 1912. Serial No. 730,534.

To all whom it may concern Be it known that I, THOMAS J. GRIFFIN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Casing\Vi'cncl1, of which the following is a specification.

This invention relates to casing wrenches adapted for use in screwing well- "asing or other tubing or pipe, and one object of the invention is to provide an even number-pf segments which are adapted to grip the pipe at diametrically opposite points and are so constructed that they can float as it were, to permit each jaw to accommodate itself to any uneven part of the casing or pipe, so that when the wrench is tightened the jaws will bear with uniformly diametrical pressures against the pipe and thereby give the maximum gripping effect, and by reason of the pressure being distributed evenly on the pipe, will avoid crushing the pipe.

Another advantage of the construction is that the removable die of each jaw, although giving maximum grippin surface, is half again smaller than it would be in a two-jaw wrench, thus making its replacement inexpensive. In case of breakage of the wrench, for example, the carrier frame, the expense of replacement is less, owing to the shortness of the segments.

A further object is to make the segment jaws interchangeable.

A further object is to provide a backing pin cooperating with one of the segments and the end of the lever for locking the wrench after it has been placed in position on the casing.

Referring to the drawings: Figure 1 is a plan view of the wrench, showing it applied to the casing, the casing being in section and the supporting chain, jerk line and weight line being partly broken away. Fig. 2 is a section on line av -:0 Fig. Fig. 3 is a side elevation of Fig. 1, looking in the direction of the arrow. Fig. f is a view similar to Fig. 2, showing a modified form of jaw.

In the form shown in Figs. 1, 2 and 3, the wrench comprises four segments 1, 2, 3 and t, segments 2 and 3 being of similar construction. The four segments are pivoted together by three connecting pins 5. The jaw has an enlarged end recessed at 6. A lever 7 is pivoted on a fulcrum pin 8 which is supported in the recessed end of the segment 1 and the lever 7 has a finger 9 which projects into a slot 10 which is formed in the end of segment 1. The outer wall of the slot 10 is rounded to form a bearing face 11 against which the finger 9 of the lever is adapted to bear. A backing pin 12 is adapted to be recessed in a hole 13 in the segment 4 and is located a slight distance from the finger 9, to give the latter a small amount of play between the bearing face 11 and the backing pin 12 to permit the angular relaxing movement of the finger 9 when loosening the segments. A supporting chain 14: is connected at one end to the lever T and at the other end to the segment 2. A jerk line 15 is connected to the end of the lever for operating the same into the position shown in dotted lines in Fig. 1, and a weight line 16 is attached to the same end of the lever for moving it in the reverse direction.

Carried by each segment is a jaw 17 In the form shown in Figs. 1, 2 and 3, this jaw is segmental as shown, and provided with gripping teeth 18, the jaw being secured to the segment by dovetail lugs 19 which engage in dovetail recesses 20 formed in the segment. This construction securely holds the jaw in place, yet permits its easy removal when desired. 21 designates the easing.

In the form shown in Fig. i the jaws 17 are segmental and pivoted at 22 to the associated segment. The strain is not borne by the pin but by a rounded bearing face 23 which is received in a concave recess 24; formed in the segment, the pin 22 serving to retain the jaw. The jaw 17 is curved on its outer face to form a clearance space 25 to allow the jaw to tilt on the pin 22 in accommodating itself to the contour of the casing. In this form I have indicated teeth 18 as being formed only on the center portion of the jaw, leaving smooth jaw portions 26 which prevent a crushing tendency on the casing, the smooth portions of the jaw acting to limit the depth of insertion of the sharp teeth during the gripping operations. Thus while the smooth portions allow a sufficient indentation of the teeth for gripping purposes, they cause an easy release for the return movement of the wrench.

In operation the backing pin 12 having been removed, the segments are swung around the easing into position shown in Fig. 1, then the lever 7 is swung around to throw the finger 9 into the slot 10 and then the backing pin 12 is inserted which looks the wrench around the casing as the backing pin limits the swing of the lever 7 to a relatively short movement and prevents its being swung far enough to bring the finger 9 out of slot 10 to permit its withdrawal. After the wrench is in place as described, by moving the lever 7 into the position shown in dotted lines in Fig. 1, the finger 9 operating against the bearing face 11 and cooperating with fulcru n S will draw all of the segments closer together and tighten the jaws against the casing and rotate the easing therewith, the jaws accommodating themselves to the contour of the casing by reason of their pivotal connection with each other. By moving the lever 7 in the reverse direction, the finger 9 will act against the backing pin 12 and spread the segments slightly, suiiicient to loosen the aws on the casing and permit the wrench to be turned reversely without exerting any reverse action on the casing. IVhen the wrench is to be removed from the casing, the backing pin 12 is lifted out and then the lever 7 may be swung far enough over to bring the finger 9 out of slot 10, whereupon segment 4: may be swung out and the other segments opened sufliciently to permit the wrench to pass off the casing. If three jaws were employed, the lines of pressure through the casing from the contacting surface of the jaws would be radial, but would not be diametrical and would not, therefore, grip the casing wit-h a positive engagement. Thus, if there were a fiat place in the casing, as often occurs, one of the three segments would be adjacent to it, but would not touch the casing, while the opposite two segments would exert radial pressure on the casing, but these lines of pressure would be at an angle to each other and have a tendency to force the casing out from between these seg ments, whereas, where there are four segments even if there is a fiat place in the casing, t ere will be another segment at least which will exert pressure against the casing at a diametrically opposite point, and will thereby positively and forcibly grip the easing and prevent slippage.

Vhat I claim is:

1. A casing wrench comprising an even number of segments pivotally connected and diametrically opposed in pairs to produce in operation a diametrical pressure through the casing engaged, a lever pivoted to one of said segments, the adjoining segment having a slot, the lever having a finger projecting into said slot, the latter segment having a pin adapted to receive the pressure of said finger, and a detachable backing pin in the latter segment, on the opposite side of said finger for receiving the opposite pressure of said finger to loosen the segments.

2. A casing wrench comprising a plurality of segments pivoted together, a lever pivoted to one of said segments, the adjoining segment having a slot, the lever having a finger projecting into said slot, the latter segment having a bearing face adapted to receive the pressure of said finger, a detachable backing pin in the latter segment, on the opposite side of said finger for receiving the opposite pressure of said finger to loosen the segments, a segmental jaw provided with a plurality of teeth arranged circularly, and means for detachably pivotally securing said segmental jaw to the segment.

3. In a casing wrench, a plurality of segments pivoted together, a let or, means connecting the lever with the segments and cooperating therewith for loosening or tightening the segments by the swinging motion of the lever, and a segmental jaw pivoted to each segment at a point intermediate of the end joints of the segment.

4. In a casing wrench, a plurality of segments pivoted together, a lever, means connecting the lever with the segments and cooperating therewith for loosening or tightening the segments by the swinging motion of the lever, a segmental jaw formed with a convex projection, a segment formed with a concave recess receiving and forming a bearing for the said projection, and a pin pivoting the jaw to the segment, concentric with said projection, said jaw being formed with a clearance between it and the segment.

5. In a casing wrench, a plurality of segments pivoted together, a lever, means connecting the lever with the segments and cooperating therewith for loosening or tightening the segments by the swinging motion of the lever, and a segmental jaw pivoted to each segment, said aw having a plurality of teeth formed thereon in the center of the jaw, the jaw having smooth frictional grlpping faces at each end.

6. A casing wrench comprising a plurality of segments pivoted together, a lever pivoted to one of said segments, the adjoining segment having a slot, the lever having a finger projecting into said slot, the latter segment having a pin adapted to receive the pressure of said finger, and a detachable backing pin, in the latter segment on the opposite side of said finger for receiving the opposite pressure of said finger to loosen the segments.

In testimony whereof, I have hereunto set my hand at Los Angeles California this llth day of October, 1912.

THOMAS J. GRIFFIN.

In presence of-- GEORGE T. HAGKLEY,

MARTHA M. LANGE.

Copies of thia patent may be obtained for W: cents each, by addressing the Commissioner 02 lateuta,

ashington, D. G. 

